When monthly sales of a product are subject to seasonal fluctuations, a curve that approxi- mates the sales has the form: 22 12 y = co+cz + sin where r is time in months. The term co + ciz gives the basic sales trend, and the sine term reflects the seasonal changes in sales. Assume you are given a set of data, (z.). i=1,2,..., ...,n and you want to find the coefficients co, c and to find the curve with the above form that best fits the given data in a least squares sense. Set up, but do not solve, the matrix and vectors needed to solve this problem.